Improvement in telegraph-insulators



M. G. FARMER.

improvement in Insulators.

N0. 1211?]99, PatentedMarch,18712.A

Unrrnn STATEs PATENT @Errea MOSES G. FARMER, OF SALEM, MASSACHUSETTS.

IMPROVEMENT IN TELEGRAPH-INSULATORS.

Specification forming part of Letters Patent No. 124,199, dated March 5, 1872.

SPECIFICATION.

To all Aahom fit may concern.'

Be it known that I, MOSES G. FARMER, ot' Salem, in the county ot' Essex and State of Massachnsetts, have invented a new and useful Improvement in Insulators for Telegraph \Yi1es; and I do hereby declare the following to be a full and correct description ol" the same, reference being had tothe accom panyin g drawing, in which the ligure represents a central application referred to. A small percentage longitudinal section of my insulator.

This invention relates to an improvement in insulators for telegraph wires; and consists, tirst, of a vul 'anite body made with a shank or tang on which a screw-thread is formed, and having a deep recess surrounding a central portion in which an ordinary metal hook is inserted; and, second, in saturating or coating the insulator with the mixture described in an application which l have made even date with this for Letters Patent for the same. The object otl this invention is the production of an insulator, which shall be as nearly as is possible in an exposed delicate device aperfect uon-coinluctor, which is so hard as to be broken only by the most violent blow, and which is of such shape as to ward ott stones and other mis` siles thrown thereat. This I accomplish as follows: K

In the drawing, A may represent the insulator as a whole. The parts a and b I form in one piece, of vulcauite, and upon the shank or tang to is formed a screw-thread, whereby the insulator is readily inserted into an auger-hole bored in the pin or bracket B. The part b is provided with a deep cavity, c, surrounding the part d, in which latter an ordinary zineplated hook7 e, is iirmly inserted. By means otl this cavity the wire is more perfectly insulated than it' the part b was made solid. As is well known, vulcanite is but a poor conductor of electricity, and hence its value as aninsulator; but, in order to render its propertyin this respect still greater, I immerse the insulator constructed after this plan in a melted mixture of rosin, bees-wax, spermaceti, or paraine, with or without oil, as described in my ot' the mixture is absorbed by the vulcanite, and the whole insulator' is evenly and nicely coated by the mixture; or, instead of this mixture I simply coat it with paratline.

Rosin, bees-wax, spermaceti, &c., all have high insulating powers, and by thus combining them with vulcanite an almost perfect insulator is produced. Being preferably round, it is protected in a great measure from missiles thrown at it, and ot itself is not easily broken, as its elasticity will break the force of the blow.

Having thus fully described my invention, what I claim, and desire to secure by Letters Patent, is-

An insulator for telegraph-wires, formed of vulcanite, in the manner described and repre sented, and supporting the ordinary wire-carrying hook, as and for the purpose set forth.

The above specification ot' my said invention signed and witnessed at Boston this 18th day ot' August, A. D. 1871.

MOSES G. FARMER.

TVitnesscs:

GnanLns S'rownLL, Gno. A. S'rownLL. 

